These perceived drawbacks of OFDM have renewed the interest in alternative modulation formats, in particular with favorable properties in terms of JRC performance. Orthogonal time frequency space (OTFS) has become a promising candidate in this respect, as it has lower PAPR [1]}, requires less frequent adaptation [2]}, has a much lower cyclic overhead [3]}, and can cope with much larger Doppler shifts [4]}. In contrast to OFDM's 2D modulation in the time–frequency domain, OTFS relies on the delay–Doppler domain. This implies that a time-varying channel with constant Doppler will appear time-invariant to OTFS [5]}. Since radar detections are of the form of range (delay) and velocity (Doppler) tuples, OTFS is a natural candidate for JRC, as evidenced by recent activity in this area [6]}, [7]}, [8]}, [9]}. Target detection and estimation of their range and velocity is done by converting the received time-domain signal back to the delay-Doppler domain. This leads to high complexity, e.g., requiring iterative interference cancellation-based processing due to significant side-lobe levels [7]}. In addition, the expression of the signal in the delay-Doppler domain is complicated (see, e.g., [9]} and [7]}), making it difficult to derive insights into the structure of the OTFS signal in terms of ISI and ICI effects. Finally, the existing approaches are limited in terms of ISI and ICI due to standard ambiguity limits in [7]}, [8]}, [9]}.
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